Forecasting
The overdraft you could have seen coming
An overdraft fee is a surprise tax on a bad week. Most of the time the bad week was visible days earlier. Here is the arithmetic your bank had and did not show you.
Dahlia Moreno, Co-founder and CEO · June 24, 2026 · 6 minute read
An overdraft fee is rarely about not having money. It is about not having money on a Tuesday, when a bill landed two days before the paycheck did. The month works out fine. The Tuesday does not.
Here is the part that stings. Your bank knew. It had your recurring bills, your regular income and your spending pattern. It could have told you on Friday that Tuesday was going to be tight. It just does not, because the fee is easier to collect than the warning is to send.
Why a forecast catches it
A forecast is just your own patterns projected forward. Tellwise learns which charges recur and when, adds a realistic amount for everyday spending, and walks your balance forward day by day. When the line dips below zero, that is the Tuesday, named in advance.
- $33B
- US overdraft and NSF fees in a year
- 48 hrs
- How long most overdrafts last
- 3 days
- Typical warning a forecast gives you
Three days is enough. It is enough to move a payment, delay a purchase, or shift money across from savings. None of that requires more income. It requires seeing the dip before you are standing in it.
The fee is not the price of being short. It is the price of being surprised.
The honest part
A forecast is an estimate, and Tellwise says so next to every one. If your income jumps around, the range is wide, and we show the range rather than pretending to a single number. But even a wide range that clearly touches zero next week is worth more than a bank statement that only tells you what already happened.
That is the whole idea of Tellwise: the same data your bank has, turned into the warning it never sends.